6 markers cost $5.58. Which equation would help determine the cost of 10 markers?
Answer: There are several equations that could help determine the cost, each with a slightly different approach. We can write the fact that 6 markers cost $5.58 as a proportion: $\dfrac{6}{\$5.58}$ Let $x$ represent the unknown cost of 10 markers. Since 10 markers cost $x$ , we have the following proportion: $\dfrac{10}{x}$ The cost changes along with the number of markers purchased, and so the two proportions are equivalent. $\dfrac{6}{\$5.58} = \dfrac{10}{x}$